Download 11.5 Speciation Through Isolation

11.5 Speciation Through Isolation
KEY CONCEPT
New species can arise when populations
are isolated.
11.5 Speciation Through Isolation
The isolation of populations can lead to
speciation.
• Populations become isolated when
there is no gene flow.
–Isolated populations adapt to their
own environments.
–Genetic differences can add up over
generations.
11.5 Speciation Through Isolation
• Reproductive isolation can occur
between isolated populations.
–members of different populations
cannot mate successfully
–final step to becoming separate
species
• Speciation is the rise of two or more
species from one existing species.
11.5 Speciation Through Isolation
11.5 Speciation Through Isolation
Populations can become isolated in
several ways.
• Behavioral barriers can cause
isolation.
–called behavioral isolation
–includes differences in
courtship or mating behaviors
11.5 Speciation Through Isolation
• Geographic barriers can cause isolation.
–called geographic isolation
–physical barriers divide population
• Temporal barriers can cause isolation.
–called temporal isolation
–timing of reproductive periods prevents
mating